Why won't my body let me sleep?

I mean, Im getting really pissy about this. Every time I fall asleep, my body sends out this violent spams and violent thrusting and mive itching every time I fall asleep. I have looked up PLMD and RLS, but I don't know. One time I tried to sleep, my body shook violently, I acutally sprained a muscle in my neck and broke one of my toes. My doctor said I was lucky that I didnt become paralyzed. Now, I'm afraid to death of going to sleep at night without waking up in the morning finding myself paralyzed. This is really affecting my everyday life and my grades in college. I get so exhausted and p out from complete exhaustion. Every time I do, my cody spams and thrust violently that I have to wake up and stay awake all the time. I don't know why Im having this problem?!!! Also with the mive itching....it only happens if I fall asleep. It never happens when Im awake. HELPPP?!